INSERT a DROPDOWN LIST in EXCEL to control what's entered in your spreadsheet. I'm all about control - except in real life!
Inserting a dropdown list in Excel works best if you create your list ahead of time. I type the list on another sheet within the spreadsheet so that it's easy to access. If you need to edit your dropdown list, you can just edit the list on the other sheet and it will update the dropdown. You can even have multiple lists on the sheet if you have other questions that need a dropdown list. I also hide the sheet with the list so that it can't be accessed by other people. To do this, right click over the sheet tab and select Hide.